1994 JAGUAR XJ6 differential

Climate Control Systems
CONTROL MODULE FAULT & CONDITION SELF-ANALYSIS
0 14.6 14.6.1 System Health
The climate control system has a 'self-test' facility, accessible from the control panel. The self test sequence has two
basic modes:
0 System error information is stored in the A/CCM up to a maximum of five faults. Should a fault occur there will
be an audible 'beep' and the message 'Er' will be displayed on the control panel LCD for approximately five (5)
seconds after ignition on. Please note that this will happen only once in any ignition switch cycle. The error
source may be accessed by the procedure described in 'Self Test System Diagnosis', this section.
0 Panel communication check may be initiated by following the instruction in 'Self Test System Diagnosis', this
section.
Nsfe: Displayed error codes are NOT directly related to Jaguar Diagnostic Equipment (JDE) but more detailed fault
related information may be accessed using Portable Diagnostic Unit (PDU).
14.6.2 System Protection
Power to the compressor clutch may be cut should either the engine management or air conditioning control systems
detect certain conditions; these conditions may be caused by Fault or Demand and can be classified thus:
0 Engine coolant overheat,
0 Refrigerant excessive pressure.
0 Refrigerant, insufficient pressure or low charge weight.
0 Speed differential between compressor and crankshaft caused by belt slippage or compressor seizure (indi-
cated by A/C state lamp flashing once per second) - 12 cylinder engine only. This feature, 'lock sensing' is fully
explained
in the EDM.
Demand
0 Engine maximum power requirement
0 Electrical system drain at engine idle.
X300 VSM 9 Issue 1 August 1994

Climate Control Systems
14.8 REFRIGERATION CYCLE:
The Compressor draws low pressure, low temperature re- frigerant from the evaporator and by compression, raises re- frigerant temperature and pressure. High pressure, hot
vaporized refrigerant enters the Condenser where it is
cooled by the flow of ambient air.
A change of state occurs
as the refrigerant cools in the condenser and it becomes a
reduced temperature high pressure liquid.
From the condenser the
liquid passes into the Receiver / Drier which has three functions,
a) Storage vessel for varying system refrigerant demand.
b) Filter to remove system contaminants. c) Moisture removal via the dessicant.
With the passage through the
receiver/drier completed the,
still high pressure liquid refrigerant enters the Expansion
Valve where it is metered through a controlled orifice which
has the effect of reducing the pressure and temperature.
The refrigerant, now
in a cold atomized state, flows into the
evaporator and cools the air which is passing through the
matrix.
As heat is absorbed by the refrigerant
it once again changes
state, into a vapour, and returns to the compressor for the
cycle to be repeated (Fig.
1).
There is an automatic safety valve incorporated in the com- pressor which will operate should the system pressure be in
excess of 41 bar. The valve will reseat when the pressure
drops below 27,6 bar.
W Thedivisionof HIGHandLOWsideissimplythesys- tem pressure differential created by the compressor
discharge (pressure), suction (inlet) ports and the
relative inlet and outlet ports
ofthe expansion valve.
This differential is critical to system fault diagnosis
and efficiency checks.
Twelve Cylinder Vehicles only:
Dual pressure switch: This two-function pressure switch
cuts electrical power to the compressor clutch if the system
pressure is outside of the range
of 2 Bar (1st Function) to 30
Bar (2nd Function).
Six Cylinder Vehicles only:
There are two switches incorporated into the high side of the
system which have the following functions:
a) Trinary; This three function pressure switch, cuts electri
-
cal power to the compressor clutch should the system pres- sure not be in a range of 2 bar (1st function) to 30 bar (2nd
function). The switch also provides a ground signal to oper
- ate the appropriate relay (within the 'Stribel,' unit) to ener- gize both engine cooling fans when maximum A/ C cooling
is required. Operation pressure, 20 bar input (3rd function).
b) Pressure Switch Slow Cooling Fans; When the system
pressure is 12 bar, medium A/ C demand, the operation of
this switch connects both engine cooling fans in series to op- erate at half battery voltage and so, half fan speed. 1.
Compressor
2. Condenser
3. Receiver / Drier 4. Expansion Valve
5. Evaporator
6. Pressure switch - Dual type
on 12
cyl & Trinary on 6 cyl
Fig. 1
0
0
Issue 1 August 1994 12 X300 VSM

Body Systems & Body Repair
Location
Centre line of the front crossmember rear mounting, at the
main floor
RH longitudinal
A4.2.2.1 Datum location, Example
The FRONT MASTER DATUM (front crossmember rear mounting at the inner face ofthe main floor RH longitudi- nal) is nominally 359,5mm to the right-hand side of the body center line. The LH side front datum is measured 717,0/ 721,Omm from the RH. Please refer to the illustration on the following page.
Expressed as
a true position in three planes, the front master datum is:
Position
X 300,O
Y 359.5 Z -50.0
0
Datum
Front Master Datum
Plan
A4.2.2.2 Key, Plan View
Please refer to the illustration on the opposite page.
Key Location
1
2
3
4
5 Driveshaft centre bearing fixings
6
7
8
9
10 Front
face body
- bumper strut / mounting point
Rearmost hole, Vee
-mount to crush tube
Front Master Datum Plan, centre line
of the front crossmember rear mounting at the main floor RH longi-
tudinal
Rearmost hole, transmission mounting
at the main floor RH longitudinal
Rear Master Datum Plan, rear longitudinal
Tapped boss, rear suspension
'A' frame mounting bush
Rear suspension spring
-pan damper mounting
Rear suspension differential strut mounting
Rear face body
- bumper strut / mounting point
X300 VSM Issue 1 August 1994 10

E 12
Rear face bodv - bumDer strut / mountina Doint
Body Systems
I
& Body
side vww
the illustration on the opposite page.
Repair
Location
Front face body - bumper strut / mounting point
Front Master Datum Vertical. centre line of the front crossmember rear mountina
Front
face body - bumper strut / mounting point
Front Master Datum Vertical, centre line of the front crossmember rear mounting
Transmission mountings
at the main floor longitudinal
Driveshaft centre bearing fixings
Rear Master Datum
Vertical, rear longitudinal
Tapped boss, rear suspension
'A' frame mounting bush
Rear suspension spring
-pan damper mounting
Rear suspension differential strut mounting
Rear face body
- bumper strut / mounting point
Transmission
mountings
at the main floor longitudinal
Driveshaft centre bearing fixings
Rear Master Datum
Vertical, rear longitudinal
Tapped boss, rear suspension
'A' frame mounting bush
Rear suspension spring
-pan damper mounting
Rear
susoension differential strut mounting
Wheel centre to
bummr cover face I
Wheel base I
Wheel centre to bumper cover face
Body Systems & Body Repair
A4.2.2.3 Key, Side Vww
Please refer to the illustration on the opposite page.
0
0
0
X300 VSM Issue 1 August 1994 12